question on low ec

[anewbie]

So one thing i haven't really understood is why heavy plant load reduces ec. I've found aquariums with lots of decaying leaves and have ec in the 40 to 80 range and this might be explained by the bacteria or whatever eating the leaves but aquariums with extremely heavy plant load have ec in the 20-22 range like this one; more so this is one of the aquariums i add some light fertilizer to support the plant load yet the ec remains very low. Now i realize ec is electrical current and perhaps the actual mineral content is ?higher? or the water might not be as soft even if the ec is low (is this possible) than those with mostly leaves or is there some other logical explanation for why the plants is reducing the ec or keeping the ec very low or maybe it is unrelated to the plants and just blind coincidence.

 

[MacZ]

Remember all dissolved solids add up on EC. So if plants use up dissolved solids like Calcium they lower EC accordingly.
Of course decomposition releases solids into the water raising EC. While not all that is released is used by plants, of course some of the compounds are used by plants. So your observation is all but unexpected.

 

[Ben Rhau]

I’ve observed this as well, and always assumed it was because the plants suck up nitrates, phosphates, and potassium from the water. Those ions are net exported out, because the plants need to be trimmed and the excess growth is removed from the tank.

 

[anewbie]

Yea of course it begs the question if fishes need some minerals or if the lower value is better - though i think in nature the ec is frequently less than 10 which might answer the question. Also i realize the use of calcium is an example but of course there should be virtually no calcium in the aquarium as the base water is ec 4 to 8 depending on if i bother to refresh the di (which is both expensive and probably unneeded).

Anyway i should post some pictures of the philodendron at some point as there was a long discussion about them - they are growing though slowly esp in the blackwater aquarium but they seem to spend more energy putting out roots than leaves

 

[Ben Rhau]

My plants tend to grow the longest roots in low EC and the biggest leaves in low light. They’re adapting to collect more nutrients/light.